We would like to propose standardizing a way of using XMLHttpRequest
to send files to the server. We propose using a similar (and
compatible) API to the Blob based API proposed by Google Gears (http://code.google.com/p/gears/wiki/BlobWebAPIPropsal
), but instead of sending Blob objects, the File objects would be
sent. This will allow the common act of uploading files, now
relegated to form submissions with an <input type="file">, to have
access to ProgressEvents and the ability to abort mid way through.
As with the Blob API, this is reuses the File and FileList interfaces
exposed by Mozilla (see http://developer.mozilla.org/en/docs/
nsIDOMFile and http://developer.mozilla.org/en/docs/nsIDOMFileList) in
a compatible. We are not proposing a specific way to get the contents
of the files, but that would be a natural future extension. Other
potential future extensions would be access to the icon associated
with the file.
Objects implementing the HTMLInputElement interface must also
implement the FileHTMLInputElement interface.
interface FileHTMLInputElement {
readonly attribute FileList files;
};
The files attribute must return a FileList containing all the files
currently selected. This list is live, and therefore updates if
contents of the input element change.
interface FileList {
readonly attribute unsigned long length
[IndexGetter] File item(in unsigned long index);
};
Each item in the FileList is File, which is a token representation of
file on the system. The fileName attribute returns just the name and
not the complete path. The fileSize attribute returns the size of the
file in bytes.
interface File {
readonly attribute DOMString fileName;
readonly attribute unsigned long long fileSize;
};
Sending a File can be accomplished with an extension to XMLHttpRequest
that overrides the existing send() method.
Objects implementing the XMLHttpRequest interface must also implement
the FileXMLHttpRequest interface.
interface FileXMLHttpRequest {
void send(File data);
};
-Sam Weinig